1. Properties of wastepaper sludge in geopolymer mortars for masonry applications
- Author
-
Kwesi Sagoe-Crentsil and Shiqin Yan
- Subjects
Paper ,Conservation of Natural Resources ,Environmental Engineering ,Absorption of water ,Waste management ,Sewage ,business.industry ,Construction Materials ,General Medicine ,Management, Monitoring, Policy and Law ,Masonry ,law.invention ,Absorption ,Geopolymer ,Portland cement ,Compressive strength ,law ,Cementitious ,Mortar ,business ,Waste Management and Disposal ,Shrinkage - Abstract
This paper presents the results of an investigation into the use of wastepaper sludge in geopolymer mortar systems for manufacturing construction products. The investigation was driven by the increasing demand for reuse options in paper-recycling industry. Both fresh and hardened geopolymer mortar properties are evaluated for samples incorporating dry wastepaper sludge, and the results indicate potential end-use benefits in building product manufacture. Addition of wastepaper sludge to geopolymer mortar reduces flow properties, primarily due to dry sludge absorbing water from the binder mix. The average 91-day compressive strength of mortar samples incorporating 2.5 wt% and 10 wt% wastepaper sludge respectively retained 92% and 52% of the reference mortar strength. However, contrary to the normal trend of increasing drying shrinkage with increasing paper sludge addition to Portland cement matrices, the corresponding geopolymer drying shrinkage decreased by 34% and 64%. Equally important, the water absorption of hardened geopolymer mortar decreased with increasing paper sludge content at ambient temperatures, providing good prospects of overall potential for wastepaper sludge incorporation in the production of building and masonry elements. The results indicate that, despite its high moisture absorbance due to the organic matter and residual cellulose fibre content, wastepaper sludge appears compatible with geopolymer chemistry, and hence serves as a potential supplementary additive to geopolymer cementitious masonry products.
- Published
- 2012